Axial Plane Deformity of the Shoulder in Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Prospective observational study. OBJECTIVE: To study axial plane deformation of the shoulder in adolescent idiopathic scoliosis (AIS) and try to correlate it with curve type and surgical correction. SUMMARY OF BACKGROUND DATA: It is established that AIS is a 3-dimensional deformity. The rib hump is the most common manifestation of axial plane deformations; the least common manifestation seems to be upper trunk and shoulder rotation, which has been hitherto undescribed. METHODS: Fourteen consecutive, operated cases of AIS were analyzed prospectively. Preoperative and postoperative x-rays of the spine and clinical photographs were studied. Clinical photographs (top view) were taken with patients in the sitting position, to show shoulder level in relation to the axis of the head and pelvis. Chest computed tomography scans were also studied to determine the direction of apical vertebra and trunk torsion. RESULTS: All 14 patients in this series had their right shoulders anteriorly rotated preoperatively (anticlockwise). The direction of rotation seemed unrelated to the curve type and shoulder elevation, although most had rib humps on the right. This shoulder rotation was corrected postoperatively by routine maneuvers done for scoliosis correction. Minor residual rotation was seen in 6 patients who also had minimal persisting rib hump. In 1 case the axial plane rotation worsened, although the shoulder level and trunk symmetry improved significantly. The apical vertebral rotation on computed tomography had little bearing on the direction of shoulder rotation. CONCLUSIONS: Axial plane rotation of the shoulder is a hitherto un-described dimension of AIS deformity complex. Much of it corrects spontaneously with correction of the thoracic spinal deformity.

Post-operative shoulder imbalance in adolescent idiopathic scoliosis: a study of clinical photographs.

STUDY DESIGN: Retrospective observational study. OBJECTIVE: To assess what features determine post-operative shoulder asymmetry in Adolescent Idiopathic Scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Shoulder balance is one of the major determinants of the cosmetic outcomes of AIS surgery. Yet, other than level of the shoulders we are not clear what parameters are to be measured to assess torso symmetry. This study looks at the various features that might affect the appearance of the shoulder region. METHODS: The records of 157 operated cases of AIS were retrospectively reviewed. Eight patients with documented post-operative shoulder asymmetry and were dissatisfied with their cosmetic outcomes were selected for the study. Their clinical photographs alone were studied. Three regions- the base of the neck, the shoulder and upper arm region- were analysed separately. Four measures each for the neck and shoulder and two for the arms were documented. No statistical tools were employed since the numbers were quite small but consensus was obtained between two Consultant Orthopaedic surgeons regarding the cosmetic impact of each parameter. RESULTS: The neck and the shoulder appeared independent determinants of cosmesis of the proximal trunk. The base of neck symmetry seemed to be dependent on four features viz. centralization of the neck, neck tilt, trapezius angle and base of neck angle. The appearance of the shoulder itself depended on its level, axillary fold level, scapular level and the scapular prominence. The upper arm parameters appeared less critical in determining the cosmetic impact. CONCLUSIONS: Proximal trunk symmetry in AIS depends on the symmetry of the base of the neck and shoulder regions. The level of the shoulders, axillary folds along with the base of neck angle, Trapezius angle appear to be key determinants of symmetry.